Adjustable seal for propeller drive shaft

ABSTRACT

An adjustable sealing device for sealing between rotatable drive shaft, such as a propeller drive shaft, and the aperture in a structure, such as the hull or bulkhead of a vessel, through which the shaft passes. The device is generally rigid and is comprised of an adapter ring, a slide ring, a diaphragm positioned between the adapter ring and the slide ring, a friction ring having one end positioned in the adapter ring and a seal surface engageable with the seal surface of a seal ring rotatable with the shaft, biasing means positioned between the slide ring and the friction ring for urging the seal surfaces together, and a spring cover acting as a seal redundant to the diaphragm.

This application is a division of U.S. patent application Ser. No.08/316,883 filed on Oct. 3, 1994, which issued as U.S. Pat. No.5,639,098 on Jun. 17, 1997.

FIELD OF THE INVENTION

The present invention relates generally to devices for creating afluid-tight seal between a rotatable shaft and a structure through whichthe shaft passes, and more particularly to a watertight seal between thepropeller drive shaft in a boat or other water vessel and an aperture inthe hull of the vessel through which the shaft passes.

BACKGROUND OF THE INVENTION

There are many design situations in which a rotatable shaft must passthrough a wall structure into a fluid medium. Often the aperture in thewall structure through which the shaft passes must be sealed in order toretain the fluid on one side of the wall. One such situation is apropeller drive shaft extending from the interior of the hull of avessel to the exterior, passing through an aperture in the hull. Theaperture must be sealed to prevent water from entering the vessel.Several devices for sealing such apertures have been developed and arediscussed below.

Stuffing boxes generally consist of a bronze or other metallic housingor plate which is fastened over the aperture in the hull of the vesseland includes a hollow, cylindrical tube which extends into the vessel.The propeller drive shaft is received in the cylindrical tube, andpasses through the housing and through the aperture. In mostapplications for pleasure craft, stuffing boxes include a metallic nut,which can be threadingly received in the cylindrical tube, inserted onthe propeller shaft. A sealing material or gland, such as packing rings,which can be wax or graphite impregnated braided flax rope is provided.The packing rings are cut and placed around the propeller drive shaftbetween the metallic nut and inside the cylindrical tube. The brass nutis then threaded into the cylindrical tube and tightened against thepacking rings, compressing the packing against the propeller drive shaftin an attempt to create an essentially watertight seal.

When stuffing boxes are used on commercial vessels having large diameterpropeller drive shafts, the packing is contained within the body of thestuffing box. Instead of the metallic nut used with pleasure craft, asdescribed above, a housing cover or cap is provided to compress thepacking. Threaded fasteners extend through the cover or cap and arereceived in threaded bores in the stuffing box.

Stuffing boxes have numerous problems. Packing seals against therotating shaft and causes wear damage to the shaft. Many problems withstuffing boxes are associated with the fact that they need constantadjustment. When the propeller shaft is operating, the packing glandshould be somewhat loose to permit adequate amounts of water to enterthe stuffing box to moisten the packing and cool and lubricate therotating shaft. If no water enters there is no lubrication and thefriction between the rotating shaft and the packing increases, causingthe shaft to become hot. This damages the packing and makes the shaftmore susceptible to being scored, and the shaft may have to be repairedor replaced.

After operation and before the vessel is docked, the stuffing box shouldbe tightened to keep all water from entering the vessel. Due to thedifficulty and inconvenience in accessing the stuffing box, most vesseloperators do not adjust it as frequently as they should. Therefore,excess water often enters the vessel when it is docked, because thestuffing box may still be loose, and a bilge pump is used to pump thewater outboard. Bilge pumps can fail or malfunction, however, and mostinboard water damage to vessels occurs because water enters through thepacking gland, and the bilge pump subsequently malfunctions.

Another major problem with stuffing boxes is that they can leak, evenwhen adjusted properly. Compressed flax is not impervious to water.Another problem with stuffing boxes is that there is very littleflexibility transverse to the axis of the shaft in a packing gland. Asthe vessel is driven backward and forward, the shaft moves back andforth and vibrates or wobbles as it rotates. The movement of the shafteventually creates gaps in the packing rings, and water leaks throughthe gaps.

Another problem with stuffing boxes is that the packing wears outquickly due to the normal rotation of the shaft. As it wears, more waterenters the vessel causing expensive vessel maintenance, both in the formof repairs to the vessel and frequent replacement of the packing. Inthis respect, when the packing is replaced, the vessel may need to belifted out of the water which is an expensive, time-consuming operation.Even when used and maintained properly, stuffing boxes need to berepacked about every six months to two years, depending on hours of useand operating conditions. To properly repack a stuffing box in somevessels, the back of the vessel may have to be removed from the water.This is expensive and inconvenient. In some situations, as whereair-sealed stuffing boxes from Duramax, Inc. are employed, the vesselneed not be removed from the water.

Another problem with stuffing boxes is that if the nut is too tight, theheat due to friction can increase to the point where the nut heats upand "freezes" to the shaft. If this happens, the stuffing box can beripped free of the hull aperture, flooding the vessel.

A additional problem with stuffing boxes is that the housing isdimensioned for one specific vessel hull aperture configuration.Stuffing boxes therefore cannot be easily retrofitted into vessels withhull aperture configurations different than that for which the stuffingbox was designed.

Another problem with stuffing boxes is that they cannot be adjusted toalign with the axis of the shaft. Therefore, the shaft is often notaligned with the cylindrical tube on the stuffing box through which itpasses, making it difficult to obtain a tight seal and to avoid damageto the shaft.

Additionally, the water which enters a vessel must be pumped outboard.Water entering the bilge through the stuffing box mixes with oil andother contaminants in the bottom of the vessel. The bilge pump pumps thewater, mixed with the contaminants, into the surrounding water. TheFederal Water Pollution Control Act prohibits discharge of oil or oilywaste into or upon navigable waters of the United States or the watersof the contiguous zone if such discharge causes a film or sheen upon ora discoloration of the surface water.

To alleviate the problems with stuffing boxes, mechanical seals weredeveloped. Mechanical seals need no repacking, little maintenance and,if properly selected and installed, virtually eliminate water fromentering the bilge. The life span of a mechanical shaft seal ifcorrectly adjusted is approximately 10,000 to 15,000 operating hours.Putting this into perspective, a busy season for a pleasure vessel is600 hours and a commercial vessel operates approximately 2,000 to 5,000hours per year. Therefore, this equates to a minimum of two years and amaximum of twenty-five years of use. The most common mechanical sealsare the "lip" seal and "face" or "surface" seal.

The lip seal is a flexible, stationary annular seal, usually made fromrubber, which surrounds and fits tightly against the propeller driveshaft creating a seal while allowing rotation of the shaft. Lip sealshave a number of problems when used in marine applications. First, lipseals tend to wear grooves in the propeller drive shaft, which isusually made of stainless steel. Once a groove is worn into the steel,water tends to leak past the groove. Further, the groove creates a weakpoint in the shaft. The shaft must then be repaired by welding orreplaced. Second, any shaft misalignment or cross-axial shaft vibrationcauses leakage because the lip seal is not flexible enough to compensatefor a shaft not centered within the seal. Third, the rubber in the lipseal must remain supple in order to conform to the surface of the shaft.The rubber seal is exposed, however, to a harsh environment of saltwater, oil, hot and cold temperatures, and loses its softness quickly,leading to water leakage.

The most popular mechanical seal used for rotating propeller shafts isthe face or surface seal. The face seal comprises two finely machinedsealing surfaces pressed together to form a watertight seal. In marineapplications, the sealing faces or surfaces are typically facing,axially-perpendicular flat sides of two annular rings, one of which ismounted on a rotating shaft, such as a propeller drive shaft. In thisrespect, each ring has an inner diameter defining a center bore oropening dimensioned such that the rings can be slidingly mounted ontothe propeller drive shaft. (Optionally, either ring can be provided intwo pieces and fastened onto the shaft whereby the pieces are joined bycompression screws.) Each ring also has an outer diameter, and a flatannular sealing surface defined between the inner and outer diameters.One of the two rings is called the seal ring and is fixed to thepropeller shaft and, therefore, rotates with the shaft. The other ringis called a friction ring, which is typically stationary and fastened toa housing through which the propeller shaft passes. The annular sealingsurface of the seal ring mates with the annular sealing surface of thefriction ring, creating a watertight seal. In standard face or surfaceseal devices, a loading or biasing means such as a spring or rubberbellows biases the friction ring and seal ring together and provides acompression force that helps create and maintain the seal.

A major advantage of a face seal is that it does not seal against thepropeller shaft. As opposed to a lip seal or to a stuffing box,therefore, face or surface seals allow the shaft to rotate with lessresistance, resulting in better performance and improved fuel economy.Additionally, the seal will not wear the propeller shaft.

One common type of surface seal uses a carbon-graphite friction ring anda stainless steel sealing ring. Although these materials usuallyfunction well, there are problems associated with them. Thecarbon-graphite friction ring is brittle, making it susceptible tocracking, and it is easily scratched or pitted, which can lead toleakage between the sealing surfaces. Further, carbon graphite andstainless steel are dissimilar materials and the contact between the twocan lead to crevice corrosion and degradation of the seal face. As itwill be understood, any imperfections in the friction ring caused bycorrosion of the surface or by scratches in the surface will causeleakage at the seal face.

Another problem which occurs with the stainless steel seal ring is thatthe ring may be secured to the shaft with set screws. The set screws areusually stainless steel and electrically connect the set screw seal faceto the shaft, promoting electrolysis on the seal face.

Another problem with surface seals is that maintaining propercompression between the two seals is critical. As the shaft moves in theaxial direction in response to the reverse or forward thrust of thepropeller, the compression between the sealing surfaces varies. Too muchpressure between the seal ring and friction ring causes undue wear ofthe seal, and too little pressure allow leakage between the seals.

It is known to use a convoluted neoprene rubber bellows to load or biasthe friction ring towards the seal ring to maintain pressure between thetwo. The biasing force of the rubber bellows is largely dependent on thedurometer of the rubber. As the rubber is exposed to the environment andages, it loses its elasticity and the amount of tension on the seal facedecreases. This results in leakage and the need to adjust the positionof the seal ring on the shift in order to compress the bellows more toincrease the compressive force between the seal ring and friction ring.

A wire-reinforced rubber bellows surface seal device was introduced inthe late 1980's. It is easy to install and remove, and it maintains agenerally constant pressure between the seal ring and friction ring,thereby extending the life of the seal. The wire-reinforced rubberbellows seal device is comprised of three main components: a rigid sterntube, a rigid friction ring and a flexible hose connecting the two. Thecenter of the hose is a bellows structure reinforced with a stainlesssteel coil spring. One end of the hose is clamped over the stern tubeand the other end is clamped over the friction ring. The propeller shaftpasses through the friction ring, the flexible hose and the stern tube.The seal ring is fixedly attached to the shaft, adjacent the frictionring. The rubber bellows and spring bias the friction ring towards theseal ring, thereby maintaining relatively constant pressure between thetwo. The spring eliminates the loss of compressive force associated withdegradation of the rubber.

It has been known to make the friction ring of the wire-reinforcedbellows of high impact, high temperature, oil-impregnated cast nylon.This material is extremely impact resistant, can withstand heat ofapproximately 350° to 400° F. and has a very low water absorption rate.Therefore, it will not crack like the brittle carbon-graphite frictionrings. Further, because it is plastic, the problems associated withcarbon-graphite seals such as electrolysis and crevice corrosion areeliminated. In addition, the seal ring can be electrically insulatedfrom the vessel. Compression screws fasten the shaft clamp to the sealring. The shaft clamp can compress a rubber or plastic O-ring againstthe seal ring thereby wedging the O-ring between the seal ring and theshaft, electrically isolating the stainless steel seal ring from thepropeller shaft.

When surface seals are in use, a thin film of water should remainbetween the two seal faces. This thin film acts as a lubricant on theseal faces and keeps the faces cool, extending the life of the seal. Ona displacement hull, bleeding off any trapped air in the seal allowswater to reach the seal faces, keeping them lubricated. On a high speedhull, a vacuum is drawn in the stern tube as the speed of the vesselincreases. Water can then be injected into the seal to keep the sealface lubricated. The wire-reinforced rubber bellows surface sealheretofore described has utilized an air vent/water injection fittingwhich can either remove air from or inject water to the sealingsurfaces.

As stated above, the wire-reinforced rubber bellows surface seal was animprovement over stuffing boxes, lip seals and other surface seals. Itprovided a surface seal arrangement wherein the friction ring would moveforward or aft by means of the flexible tube and spring-loaded bellows,in response to axial movement of the propeller shaft and the seal ringfixed to the shaft. Therefore, surface pressure between the two sealingsurfaces was constantly maintained without the sealing faces beingexcessively compressed. This seal still had a number of problems,however. First, because the rubber hose is soft and flexible, it can bemoved or dislodged by a person stepping on it or by objects striking it.When the rubber hose is moved or dislodged, the seal faces are moved outof alignment, thus interfering with the sealing contact, and substantialleakage occurs. Additionally, as with all prior art seals, this sealcannot be adjusted to the axis of the propeller shaft after it isinstalled, nor can it be easily retrofitted onto different vesselhull/aperture configurations.

The present invention overcomes the disadvantages of the prior art byproviding an adjustable surface or face-sealing device, easily adaptableto most hull aperture configurations, which can be aligned with the axisof the propeller drive shaft after it is installed, and which isconstructed of rigid components so that force applied to the device willnot dislodge the sealing surfaces.

BRIEF SUMMARY OF THE INVENTION

In accordance with the preferred embodiments of the invention, there isprovided a shaft seal system for use with a vessel, such as a vessel,where the drive or propeller shaft extends from an inboard engine orgear box, through the hull or bulkhead, to an outboard drive means, suchas a propeller. The shaft seal system prevents the flow of water throughthe opening in the hull or bulkhead, into the vessel and out of theconfines of the system. Considering the system from aft to forward,there is provided an appropriate adapter that fills the hull opening,and which is connected to adapter ring which is connected to a seagasket or diaphragm which is in turn connected to a slide ring and to afriction ring. The friction ring has a seal face which is engageablewith the seal face of the seal ring as discussed later, and a rearwardlyextending body which goes around the shaft. The diaphragm is attached tothe friction ring body. Between the slide ring and the friction ring arebiasing means, such as a tension spring, for loading or biasing thefriction ring forwardly to put enough pressure on the seal surface ofthe seal ring to establish a dynamic and a static watertight seal. Theseal ring is connected to and held in place on the shaft by a shaftclamp. A spring cover extends over the tension spring and is attached tothe slide ring and to the friction ring. As described below, the flow ofwater is precluded or prevented by the diaphragm, and the spring coveris redundant to the diaphragm.

This unit is rigid, and it will not be disrupted if it is stepped on orimpacted during the use of the device. This is a very important featureof the invention, since this is one of the major causes of catastrophicfailure of the prior art devices.

Another important feature of the invention is the adapter ring and thecomponents which are used with it. The adapter ring enables the systemto be used with many other devices through which the propeller shaftpasses in penetrating the bulkhead or hull of the vessel. As discussedbelow, the adapter ring is internally threaded for receiving the threadof a variety of cooperating components. For example, a thru-hull adapterring can be extended through the hull of a ship and its external threadscan be threaded into the internal threads of the adapter ring, to holdthe system in place and prevent the flow of water into the vessel andout of the shaft seal system. Alternatively, a flange ring could be usedfor attaching the system to a stern tube which runs through an openingin the hull, or the flange ring itself could be attached to the hull. Inanother well-known arrangement, a hose adapter can be connected to theadapter ring, and also to a hose which leads to a stern tube whichextends through the opening in the hull of the vessel for providing apath for the shaft into the vessel.

An important part of the preferred embodiment of the invention are themeans for preventing the flow of water through the system. Inparticular, the diaphragm, such as a sea gasket, must be able to preventthe flow of water out of the shaft seal system, but also must besufficiently flexible to allow the friction ring to move fore and aft asthe shaft moves fore and aft. The diaphragm has an annular section whichis connected to the friction ring. The diaphragm is configured toreceive one or more O-rings as a clamp for attaching the diaphragm tothe friction ring in a watertight manner, and the friction ring isconfigured to receive the diaphragm with the O-rings clamping theconnection. The other end of the diaphragm includes an annular sectionwhich is attached to the slide ring by screws, such as centering screws.The arrangement with the centering screws enables the changing of thelongitudinal axis of the passage through the system as the axis of theshaft changes. The coaxial centering screws thus enable the longitudinalaxis of the passageway to be coaxial with the longitudinal axis ofrotation of the propeller shaft. A convoluted section of the diaphragmconnects the two annular attachment sections. The diaphragm is able tomove fore and aft because of the flexibility provided by theconvolutions to enable the diaphragm to serve its watertight function.The slide ring is another important part of the preferred embodiments ofthe invention. The slide ring is required in order to provide a mountinglocation for the diaphragm. The slide ring also provides a supportstructure for the tension spring which urges the friction ring towardsthe seal ring. Also, the slide ring cooperates with the friction ringand guides the friction ring during its limited axial movement as theshaft moves fore and aft.

The flexible nature of the system, referring specifically to thediaphragm and the spring cover, enables the seal surface of the frictionring and the seal ring to remain effective even if they become somewhatmisaligned, while not impairing the important rigidity of the system.

It is an object of the present invention to prevent water from enteringa vessel and leaving the confines of the shaft seal system according tothe invention, where the vessel has a propeller shaft extending from aninboard motor or gear box to an outboard propeller.

Another object of the invention is to provide a system for preventingwater from entering a vessel having a shaft which extends through thehull or bulkhead of the vessel, even if the shaft of the vessel changesits position radially or axially.

Still another object of the invention is to provide a system forpreventing water from entering a vessel having a propeller shaft whichextends through the hull or bulkhead of the vessel, where the system isrigid and can withstand impact forces which might damage or dislodgeother shaft-sealing systems.

Still a further object of the invention is to provide a water-sealingsystem for a vessel which remains effective even if portions of thesystem become misaligned during operation of the system.

It is also an object of the invention to provide a system as describedabove which contracts and elongates in order to adjust for axialmovement of the drive shaft during the operation of the vessel toprevent damage to the sealing components of the system an(d to maintainthe integrity of the seal.

It is yet another object of the invention to provide a system forsealing against a flow of water where the longitudinal axis of thesystem moves from the axis of the drive shaft.

A further object of the invention is to provide a fluid-sealing devicefor a vessel having a shaft which runs through the hull or bulkhead ofthe vessel which can be used with many different types of apparatus forreceiving a shaft where it extends through the hull or bulkhead.

Another object of the invention is to provide a fluid-sealing device foruse with a vessel having a shaft which extends from a motor or gear boxinboard to a propeller outboard of the vessel, which can easily be usedwith various types of thru-hull adapter rings, flange adapters, hoseadapters, stern tube clamp adapters and the like through which propellershafts extend through the hull or bulkhead.

Another object of the present invention is to provide a device asdescribed above to which adapters may be attached, each respectiveadapter adapting the device for mounting to a different hull apertureconfiguration.

Another object of the present invention is to provide a sealing deviceas described above wherein the friction ring is made of a durablematerial such as oil-impregnated nylon.

Another object of the present invention is to provide a device asdescribed above which includes a secondary seal in case one of theprimary seals fails.

Another object of the invention is to provide a water-seal apparatus forthe shaft of a vessel which is safe in operation, durable and easy tomake, uses known components and raw materials, and which furthermore iseffective, efficient and reliable in operation.

Other objects will become apparent from the description to follow andfrom the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a preferred embodiment of the present inventionused in conjunction with a propeller drive shaft of a vessel.

FIG. 2 is a side, partially cut away, sectional view of the system shownin FIG. 1.

FIGS. 3A and 3B are exploded views of the system shown in FIG. 1.

FIG. 4 is a partial, enlarged view showing the front portion of thedevice shown in FIG. 2.

FIG. 5 is a partial enlarged view showing the back portion of the deviceshown in FIG. 2

FIG. 6 is a partial longitudinal section view, in partial cross section,showing the device dented in FIG. 1 in a compressed position.

FIG. 7 is an end view of the adapter ring shown in FIG. 1.

FIG. 8 is a cross-sectional view of the adapter ring shown in FIG. 7.

FIGS. 9, 10 and 11 are end, side and cross-sectional views,respectively, of a diaphragm used in FIG 1.

FIGS. 12 and 13 are end side views of a slide ring used in accordancewith the apparatus of FIG. 1.

FIGS. 14 and 15 are end and side views, respectively, of a friction ringused in the apparatus of FIG. 1.

FIG. 16 is a side view of a coil spring used in the apparatus of FIG. 1.

FIG. 17 is a side view of a spring cover in accordance with the systemof FIG. 1.

FIGS. 18 and 19 are end and side views, respectively, of a thru-hulladapter ring used with the system of FIG. 1.

FIGS. 20 and 21 are side and end views, respectively, of an adapterflange usable with the system of FIG. 1.

FIG. 22 is a side view of a hose adapter for connecting a stern tube toan adapter ring pursuant to the present invention.

FIG. 23 is a side view of a second embodiment of the present inventionmounted on a propeller drive shaft.

FIG. 24 is a side view of a third embodiment of the present inventionmounted on a propeller drive shaft.

FIG. 25 is a side view of a fourth embodiment of the present inventionmounted on a propeller drive shaft.

FIG. 26 is a side view of a fifth embodiment of the present inventionmounted on a propeller drive shaft.

FIG. 27 is a side view of a sixth embodiment of the present inventionmounted on a propeller drive shaft.

FIG. 28 is a side view of a seventh embodiment of the present inventionmounted on a propeller drive shaft.

FIGS. 29 and 30 are front and side views of a hose adapter according tothe invention.

FIG. 31 is a partial, side, partially cut-away view of a stern tubeclamp adapter connected to a stern tube through which a propeller shaftextends, according to an eighth embodiment of the invention.

FIG. 32 is a partial, side, partially cut-away view of a stern tribeseal assembly according to a ninth embodiment of the invention.

FIG. 33 is a partial, side, partially cut-away view of an air sealassembly according to the invention.

FIG. 34 is a partial, side, partially cut-away view of a tenthembodiment of the invention incorporating an air seal shown in FIG. 33.

FIG. 35 is a partial, side, partially cut-away stern tube clamp sealassembly according to the invention.

FIG. 36 is a partial, side, partially cut-away hose bearing adapteraccording to the invention.

FIG. 37 is an end view of the hose bearing adapter shown in FIG. 36.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Turning now to the drawings where the purpose is for illustrating apreferred embodiment of the invention, a shaft sealing device 10 forsealing between a shaft 12 and a wall structure such as a hull 14 isshown in FIG. 1. The right and exterior end of shaft 12 is connected tothe propeller of the vessel, and the left and interior end is connectedto the engine or gear box of the vessel. Sealing device 10 has apassageway for the shaft with a generally longitudinal axis A, whichalso should be the axis of rotation of shaft 12. Sealing device 10 iscomprised of an adapter ring 20, a sea gasket or diaphragm 50, a slidering 62, a friction ring 90, and a loading or biasing means 130 (FIG. 2)within a spring cover 134. A seal ring 161 is affixed to shaft 12 andheld there by a shaft clamp 163. A safety shield 170 is attached tofriction ring 90.

Turning now to FIGS. 2 and 3, adapter ring 20 is generally a hollowcylindrical tube hiving a wall 22. Wall 22 has an annular outer surface24 and an annular inner surface 26, which are best seen in FIGS. 2, 4,5, 7 and 8. Inner surface 26 defines a generally cylindrical cavity 28.Adapter ring 20 has a first end 30 and a second end 32, as is best seenin FIG. 8, each end being open and communicating with cavity 28. Amounting surface 34 is generally planar and radial and is formed in wall22 at the first end 30 of adapter ring 20. Four equally radially spacedmounting bores 36 are formed in surface 34. Bores 36 are aligned alongrespective longitudinal axes (not shown) which are parallel to axis A.Angled recess 38 is formed in surface 34 adjacent cylindrical innersurface 26.

A receiving portion 40 is formed in wall 22 at the second end 32 ofadapter ring 20 and extends perpendicularly from wall 22 into cavity 28.Section 42 of receiving portion 40 is threaded as shown at item 44 inthe preferred embodiment and can be threadingly engaged with adaptersections, as will be discussed in detail below.

Diaphragm 50, best seen in FIGS. 2, 9, 10 and 11, is flexible andpreferably formed of rubber or other resilient material which isresistant to salt water. Diaphragm 50 includes a radial base 52, aconvoluted body 54 and an annular foot 56. Base 52 is generally smoothand perpendicular to axis A and has four equally radially spacedapertures 58, best seen in FIGS. 3 and 11, formed therein and an outerannular edge 60. Base 52 is mounted on mounting surface 34, as best seenin FIGS. 2 and 5, with apertures 58 aligned with mounting bores 36.Outer edge 60 of base 52 extends beyond cylindrical outer surface 24, ascan be seen in FIGS. 2 and 5. O-rings 61 hold the rearward part ofdiaphragm 50 to the rearwardly extending body of friction ring 90.

Convoluted body 54 extends from base 52 into cavity 28. Foot 56 isformed at an angle to leg 54 and is generally parallel to axis A and isattachable to friction ring 90 to create a watertight seal, as will bediscussed below.

Slide ring 62, best seen in. FIGS. 2, 3B, 12 and 13, is generally ahollow, cylindrical tube having a wall 64 composed of a series ofannular surfaces, and a radial base 66 which is perpendicular to wall64. Wall 64 has an outer surface 68 and an inner surface 70 defining acavity 72 adjacent cavity 28. Slide ring 62 has a first end 74 and asecond end 76, best seen in FIG. 13, wherein each end is open and incommunication with cavity 72. A support surface 78 is generally flat andannular and is formed at the first end 74 of base 66. Base 66 has fouror more apertures 80 equally radially spaced thereabout. The outerdiameter of base 66 is approximately equal to the diameter of theannular outer surface 24 of adapter ring 20.

Slide ring 62 is attached to adapter ring 20, as is best seen in FIGS.1, 2 and 5, with gasket 50 disposed therebetween. When mounted, the baseof slide ring 62 is positioned against base 52 of gasket 50. Apertures80 align with apertures 58 in gasket 50 and mounting bores 36 in adapterring 20.

Centering screws 82, best seen in FIGS. 2, 3 and 5, are provided andpass through flat washers 83, apertures 80, apertures 58 and arethreadingly received in mounting bores 36, thereby fastening slide ring62 to adapter ring 20 with diaphragm 50 disposed therebetween. Centeringscrews 82 can be loosened or tightened in mounting bores 36 therebymoving in a linear direction parallel to axis A. When centering screws82 are moved, slide ring 62 moves in response, as will be discussed inmore detail below.

Friction ring 90, best seen in FIGS. 2, 3, 4, 5, 6, 14 and 15, isgenerally a series of integral, coaxial, hollow cylinders 101, 103, 105,110 and 111. Cylinder 103 has a cylindrical outer surface 92 and acorresponding cylindrical inner surface 94 defining a cylindrical cavity96 through which the shaft 12 passes. Cylinder 101 is located at an end98 of friction ring 90, best seen in FIGS. 5 and 15, and includes anannular channel 100. Channel 100 has a smooth, annular surface which isgenerally concentric with surfaces 92 and 94. A lip 104 is annular andextends outward from channel 100, lip 104 forming one end of frictionring 90. A wall portion 106 connects channel 100 with outer surface 92.Channel 100 provides a mounting location for foot 56 of gasket 50. Foot56 is attached to channel 100 by an O-ring 108, as seen in FIGS. 2, 3and 5, creating a watertight seal between gasket 50 and friction ring90.

Cylinder 110, best seen in FIGS. 2, 4, 15 and 16, includes an interiorannular wall 112 defining an internal cylindrical cavity 114 throughwhich shaft 12 passes and which aligns with and communicates with cavity96. Cavity 114 has a diameter larger, preferably 1/4" or more larger,than the diameter of shaft 12. Sealing portion 116 is formed on theforward-facing side of cylinder 110. Cylinder 110 has an outsidediameter slightly smaller than that of the annular outer surface 24 ofthe adapter ring 20. Cylinder 110 includes a bore 122 for attachment ofa hose barb 124, shown in FIGS. 1, 2, 3 and 5. Hose barb 124 isconnectable to a hose for an air vent (not shown) or a water supply (notshown).

A sealing surface 126 is generally flat and annular and is formed on theforward-facing side of sealing portion 116. Cylinder 105 has an outerannular surface 132 which has an outside diameter smaller than theoutside diameter of cylinder 110 and greater than the diameter of wall92 of cylinder 103. Cylinder 105 has a rearwardly disposed radialretention surface 128. Retention surface 128 is generally flat andannular and perpendicular to surface 92 of cylinder 103.

A biasing or loading means shown as a seal tension spring 130, best seenin FIGS. 2, 3, 4, 5 and 16, is a helical spring preferably formed ofstainless steel or a non-metallic, or a noncorrosive material, or amaterial with a noncorrosive component. Spring 130 surrounds outercylinder 103 and is retained between retention surface 128 at one endand by a support surface 78 of slide ring 62 at the other end.

A spring cover 134, best seen in FIGS. 1, 2, 3, 4, 5, and 17, has twoend portions 136 and a center bellows portion 138. Spring cover 134 ishollow, flexible and surrounds spring 130. Cover 134 can advantageouslybe a urethane product. An end portion 136 of cover 134 mounts over outerannular surface 132 of cylinder 110 and butts against cylinder 105 andis fastened to the outside edge of cylinder 105 by a fastener, which ispreferably a pair of O-rings 108, creating a watertight seal. The otherend 136 of spring cover 134 is fastened to the outer surface 68 of slidering 62 by a pair of O-rings 108, creating a watertight seal.

Means are required for allowing passage of the propeller shaft throughthe vessel hull to the water-seal system. In FIGS. 1 and 2, a thru-hulladapter 142 is attached to the second end 32 of adapter ring 20.Referring to FIGS. 2, 18 and 19, thru-hull adapter ring 142 has aconnecting end, such as a threaded, tubular end 144, which isthreadingly received in section 42 of receiving portion 40 of adapterring 20, and an adapter end or flange 146 which adapts device 10 to aspecific vessel hull configuration. Tubular end 144 has a bore with adiameter for receiving propeller shaft 12. Bores for receiving shaftshaving ODs of 3/4 to 12" have been used, although the invention is notlimited to that range of sizes. Adapter flange 146 has a set of radiallydisposed, longitudinal recesses 147 for receiving a tool for turningadapter ring 142 to tighten flange 146 against the vessel hull. It willbe appreciated that adapter end 146 of component 142 can have anyconfiguration and ring 142 will be chosen so that it has an adapter end146 capable of adapting device 10 to the specific vessel hull/apertureconfiguration desired.

Other components for leading a propeller shaft through the hull orbulkhead of a vessel are shown in FIGS. 20, 21 and 22.

FIGS. 20 and 21 show an adapter flange 148 having a threaded, tubularend 149. A flange 150 has apertures 151 which align with apertures in aplate in the vessel's hull. Standard fasteners (not shown) attach theadapter flange to the plate, and the propeller shaft extends through thetube and into the water-sealing apparatus.

In FIG. 22, an adapter ring 20 is mounted for receiving the propellershaft. A hose adapter 155 has its threaded forward portion 157 screwedinto adapter ring 20. The rearward end of hose ring 155 extends to hull14. A stern tube 158 is attached to hose adapter 155 at rearwardlyextending portion 157A by an elastomeric hose 156, such as a rubberhose. A radial wall or shoulder 155A limits the amount hose 156 can beplaced on portion 157A. Hose clamps 159 attach hose 156 between hoseadapter 155, adapter ring 20 and stern tube 158.

Turning now to the operation of sealing device 10, device 10 is insertedonto the propeller drive shaft, as is best seen in FIGS. 1 and 2, withthe friction ring 90 and its sealing portion 116 facing the engine ofthe vessel, and the adapter ring 20 being adjacent the hull of thevessel. The device 10 is attached to the hull by means of the thru-hulladapter ring 142, adapter flange 148, or hose adapter 155 and stern tube158, each of which extends from the exterior of the hull, through thehull, or from an opening on the interior side of the hull, and isconnected to adapter ring 20 such as by the threading engagement of thescrew threads of the adapter ring and the thru-hull adapter ring or thelike. The thru-hull adapter, flange adapter, or the hose adapter andstern tube or others are specifically selected for the hull/apertureconfiguration of the vessel.

The propeller drive shaft 12 has a shaft clamp 163 fixedly mounted toit. Seal ring 161 is attached to shaft clamp 163 by longitudinallyextending connection screws 165. Seal ring 161 has a flat,rearwardly-facing seal surface 160. A shaft clamp 163 is mounted againstseal ring 161 and fastened to seal ring 161 by compression screws 165.Shaft clamp 163 holds seal ring 161 in position so that its seal surfaceengages flat radial seal surface 126 of friction ring 110. Clamp 163 isheld fast on the shaft by clamp screw 167, which forces the free ends ofclamp 163 towards each other. An O-ring 169 is clamped between clamp 163and seal ring 161 to stop water from leaking between the seal ring 161and shaft 12. A safety shield 170 is attached to friction ring 50 byself-tapping screws 172 or other fastener devices, and extendsforwardly.

Once device 10 is mounted it should be adjusted to align axis A of thedevice with the axis of shaft 12. This is accomplished by looseningand/or tightening the respective centering screws 82. When eachrespective screw is tightened into the bore 36 into which it isthreadingly received, it draws the portion of base 66 proximate the bore36 closer to gasket 50 and adapter ring 20. This skews base 66, slidering 62, friction ring 90 and friction ring 110 thereby altering theirlinear alignment. Similarly, when a respective screw 82 is loosened itpushes against the threads in the bore 36 into which it is received andmoves the portion of base 66 proximate to the respective bore 36 awayfrom gasket 50 and adapter ring 20. This skews base 66, slide ring 62,friction ring 90 and friction ring 110 in the opposite direction,thereby altering their linear alignment. The friction ring 90 and slidering 62 can thereby he aligned with axis A of shaft 12 by appropriateloosening and/or tightening the respective screws 82. Preferably,friction ring 90 and slide ring 62 will be aligned so that shaft 12 iscentered in the cavity 114 of the friction ring.

During the operation of the engine, propeller shaft 12 rotates and sealring 161, shaft clamp 163 and O-ring 169 rotate with the shaft. Device10 is stationary because the cylindrical cavity 114 aligned along axis Adefined by the above-described components of the device is larger thanthe outside diameter of the propeller shaft and the shaft is allowed torotate freely. Seal ring 161 contacts and rides against stationarysealing surface 126 forming a watertight surface or face seal, as seenin FIGS. 2 and 4. Spring 130 biases or loads friction ring 90 andsurface 126 towards ring 161 and creates enough pressure between surface126 and ring 161 to maintain a watertight seal.

Water (W) entering through the gap between the propeller drive shaft andthe hull of the vessel passes into the inner cavity 14 of device 10.Much of the water is channeled past outer lip 104 into a cavity 180defined between leg 54 and foot 56 of gasket 50 and cylindrical innersurface 26 of adapter ring 20. This water is blocked by leg 54 ofdiaphragm 50. In the event diaphragm 50 should fail, the water wouldpass between outer surface 92 of cylinder 103 of friction ring 90 andinner surface 70 of slide ring 62 into a cavity 182 defined betweensurface 92 and spring cover 130. In such a case, spring cover 130 wouldprovide a backup seal and keep the water from entering the inside of thevessel.

Water entering the narrow channel defined between the shaft 12 and theinterior surface 94 of cylinder 103 is blocked by the surface or faceseal formed between sealing surfaces 126 of friction ring 90, seal ring161 and by O-ring 169.

When the vessel is operating, the forward or rearward thrust of thepropeller causes the propeller shaft 12 to move, either forwards,towards the engine, or aft, towards the propeller, along axis A. Whenthe vessel is driven forward, propeller shaft 12 is pushed along axis Atowards the engine. This moves the seal ring 161 away from surface 126.Spring 130 has enough compressive force to move friction ring 90 and,hence, surface 126 towards seal ring 161 in order to maintain contactbetween surfaces 126 and seal ring 161 with enough pressure between themto form a watertight seal. In this situation, as friction ring 90 isbiased towards the engine, the bellows portion 138 of spring cover 134unfolds and expands. Indented end 98 of friction ring 90 moves linearlyalong axis A towards the engine, thus moving foot 56 of gasket 50 inresponse. Fasteners 108 maintain a watertight seal between foot 56 andchannel 100 during this movement.

When the vessel is driven backward, propeller shaft 12 is pulled alongaxis A towards the propeller, as is best seen in FIG. 6. This moves theseal ring 161 towards surface 126, applying force pressure to frictionring 110 and compressing spring 130. Spring 130 is flexible andcompresses to allow the friction ring 90 to move towards the propellerin response to the force exerted on surface 126 by ring 161.Importantly, spring 130 is flexible enough so that the pressure betweensurface 126 and ring 161 remains relatively constant and does notincrease to the point where the rotation of ring 161 will score orotherwise damage surface 126.

When spring 130 compresses, the bellows portion 138 of spring cover 134collapses and indented portion 98 of cylinder 103 is pushed towards thepropeller. Foot 56 of gasket 50 is fastened to channel 100 by O-ring 108and is pulled toward the propeller in response to the movement ofcylinder 103. Leg 54 is thereby stretched and is supported by angledrecess 38, angled recess 38 being formed so as not to have a sharp edgewhich may cut or damage leg 54.

Having described the preferred embodiment, alternative embodiments willnow be described. Components similar to those in the preferredembodiment will be given like designations and particular emphasis willbe placed on different components and structure.

FIG. 23 shows an alternative embodiment 1010 specifically designed tosupport the friction ring to insure that it is aligned with axis A ofshaft 12. An adapter ring 1020 is a short, hollow cylindrical tubehaving an annular wall 1022 and a cylindrical inner cavity through whichshaft 12 passes. A flat, radial surface 1024 is formed along one sideand is perpendicular to wall 1022, and an opposing flat radial surface1025. An elongated receiving portion 1040 defines a cylindrical interiorcavity (not shown) through which shaft 12 extends and has a threaded,annular exterior wall 1042 which receives adapter components (notshown), such as a thru-hull adapter ring discussed earlier. A pluralityof radially spaced bores 1026 are formed in surface 1024 parallel toaxis A. Bores 1026 extend through wall 1022.

A flat gasket or diaphragm 1050 contains spaced apertures 1058 formed toalign with bores 1026. Gasket 1050 includes a radial face 1052 mountedon annular ring 1020, as shown in FIG. 23. A set of bores 1058 are inalignment with bores 1026.

A slide ring 1062 includes a base 1064 and an outer cylinder 1066extending from base 1064 in a direction generally parallel to axis A.Base 1064 is mounted on gasket 1050, compressing gasket 1050 betweenbase 1064 and adapter ring 1020. Cylinder 1066 extends longitudinallytowards the engine and terminates at an open end disposed radiallyoutwardly from shaft clamp 163.

Fasteners 1082, which are preferably centering screws, pass throughbores 1026 and apertures 1058 and are threadingly received in bores 1059in slide ring 1062, thereby fastening slide ring 1062 to adapter ring1020 with gasket 1050 interposed therebetween.

A friction ring 1090 is composed of a set of three integral hollow,peripherally oil-impregnated plastic or other material cylinders 1101,1105 and 1110. Cylinder 1101 has a cylindrical outer surface 1092 anddefining a cavity through which the shaft 12 passes. One end of frictionring 1090 is received in the inner cavity of adapter ring 1020 where itcontacts face 1025 of adapter ring 1020 and the periphery of surface1064 of slide ring 1062.

Cylinder 1105 is a guide ring and a sealing portion. Cylinder 1105 hasan outer annular surface 1118 which has a diameter greater than thediameter of cylinder 1101 and a spring compression surface 1120, whichis generally flat and radial and extends about the periphery ofcylindrical outer surface 1092. Cylinder 1110 is a sealing portionhaving an annular outer surface 1122, which has a diameter less than thediameter of outer annular surface 1118 of guide ring 1105, and a sealface 1124 which is generally flat and radial.

A loading or biasing means 1130, which in the preferred embodiment is astainless steel coil spring, is provided oil cylinder 1101 and isretained and compressed between base 1064 and spring retention surface1120 of guide ring 1105.

Outer surface 1118 of guide ring 1105 has a diameter approximately equalto the inner diameter of cylinder 1066. Guide ring 1114 is therebycontained within and supported by cylinder 1066. Cylinder 1066 guidesthe guide ring 1114 along the longitudinal axis of cylinder 1066. Thefriction ring 1090 can thereby be accurately aligned in order tomaintain a seal between surface 1124 and the seal surface of seal ring161.

Turning now to the operation of sealing device 1010, device 1010 isinserted onto the propeller drive shaft with the friction ring 1090facing the engine of the vessel, and the adapter ring 1020 beingadjacent the hull of the vessel. Device 1010 is attached to the hull bymeans of a thru-hull adapter ring or the like, which is specificallydesigned for the hull/aperture configuration of the vessel and extendsthrough an opening in the hull, and is threadingly received on receivingportion 1040 of adapter ring 1020.

Once device 1010 is mounted it should be adjusted to align its axis Awith the axis of shaft 12. This is accomplished by loosening and/ortightening the respective centering screws 1082. When each respectivescrew is tightened into the bore 1068 into which it is threadinglyreceived, it draws the portion of base 1064 proximate the bore 1058closer to gasket 50 and adapter ring 1020. This skews base 1064 andfriction ring 1090, thereby altering their linear alignment. Similarly,when a respective screw 1082 is loosened it pushes against the threadsin the bore 1058 into which it is received and moves the portion of base1064 proximate to the respective bore 1058 away from gasket 1050 andadapter ring 1020. This skews base 1064 and friction ring 1090 in theopposite direction, thereby altering their linear alignment. Thefriction ring 1110, friction ring 1090 and base 1064 can thereby bealigned with axis A of shaft 12 by loosening and/or tightening therespective screws 1082. Preferably, friction ring 1090 can be aligned sothat shaft 12 is centered in the opening in the friction ring.

A shaft clamp or collar 163 is mounted tightly on shaft 12 by screws 167and is connected to seal ring 161 by longitudinally connecting screws orthe like, holding it in a fixed position so that its seal surface 160 isheld against flat radial seal face 1124 of friction ring 1090. An O-ring(not shown, but as discussed earlier with respect to O-ring 169) isclamped between clamp 167 and seal ring 161 to stop water from leakingbetween the seal ring 161 and shaft 12.

During the operation of the engine, propeller shaft 12 rotates and sealring 161, clamp 167 and the O-ring rotate with the shaft. Device 1010 isstationary because the cylindrical cavity extending through the deviceis larger than the diameter of the propeller shaft; therefore, the shaftextending through the stationary hull is allowed to rotate freely. Theseal surface 160 of seal ring 161 contacts and rides against stationarysealing surface 1124 forming a watertight surface or face seal. Spring1130 biases or loads friction ring 1110 and surface 1124 towards ring161 and creates enough pressure between surface 1124 and ring 161 tomaintain a watertight seal.

When the vessel is operating, the forward or rearward thrust of thepropeller causes the propeller shaft 12 to move, either forwards,towards the engine, or aft, towards the propeller, along axis A. Whenthe vessel is driven forward, propeller shaft 12 is pushed along axis Atowards the engine. This moves the seal ring 161 away from surface 1124.Spring 1130 has enough compressive force to move friction ring 1090 andsurface 1124 towards seal ring 161 in order to maintain contact withenough pressure between surface 1124 and ring 161 to form a watertightseal.

When the vessel is driven backward, propeller shaft 12 is pulled alongaxis A towards the propeller. This moves the seal ring 161 towardssurface 1124 applying pressure to friction ring 1110 and compressingspring 1130. Spring 1130 is flexible and compresses to allow thefriction ring 90 to move towards the propeller in response to the forceexerted on surface 1124 by ring 161. Importantly, spring 1130 isflexible enough so that the pressure between surfaces 1124 and ring 161remains relatively constant and does not increase to the point where therotation of ring 161 will score or otherwise damage surface 1106.

Turning now to FIG. 24, a third embodiment 2010 of the present inventionis shown installed on a propeller drive shaft 12. Device 2010 is similarin design to device 1010 shown in FIG. 23. Therefore, identicalstructures and components will not be identified in a great detail here,it being understood that they were described in the description ofdevice 1010. Particular emphasis will be placed on the differentfeatures in device 2010. As with device 1010, device 2010 isspecifically designed to support the friction ring 2090 and insure thatit is aligned with the axis of shaft 12. Adapter ring 2020 is a short,hollow cylindrical tube having a smooth, annular, outer wall 2022 and anelongated receiving portion 2040 having a threaded annular outer wall2044. The diameter of walls 2022 and 2044 are approximately equal,receiving portion 2040 being designed to threadingly receive an adaptercomponent 142 or the like, as is described in greater detail above. Aninterior cavity (not shown) is defined through adapter ring 1020, andshaft 12 passes therethrough. Sea gasket 2050 is in all respects thesame as sea gasket 1050 and will not be described in detail here. Slidering 2062 is identical to slide ring 1062 except that cylinder 2066 isshorter than cylinder 1066. Cylinder 2066 extend in a directiongenerally parallel to axis A to a point approximately half way across anannular outer surface 2118 of a guide ring 2114. Furthermore, there areno adjustable attachment means, such as centering screws, attachingslide ring 2062 to adapter ring 2020. Slide ring 2062 is instead fixedlyattached to housing 2020.

Turning now to FIG. 25, a fourth embodiment 3010 of the presentinvention is shown mounted onto a rotating shaft 12, such as a propellerdrive shaft. Sealing device 3010 defines a generally cylindrical bore(not shown) therethrough, through which shaft 12 passes. As will bedescribed below, device 3010 is specifically designed for shafts havingextreme eccentric movement or wobble. Sealing device 3010 is comprisedof a hose 3020, a friction ring 3090, a seal ring 161, a biasing orloading means 3130 and a shaft clamp 163.

Hose 3020 is basically a cylindrical hose having a cylindrical outerwall 3024 and a cylindrical inner cavity through which shaft 12 passes.Hose 3020 is flexible and resilient and is preferably made of rubber orplastic and rubber. One end (not shown) of hose 3020 is fitted over theinterior end of a stern tube (not shown) and the other end 3026 isfitted over a portion of friction ring 3090 as will be discussed below.

Friction ring 3090 is comprised of three integrally formed, generallycylindrical components, a support section 3116, a center portion 3118and a sealing section 3120. Support section 3116 is generally a hollowcylinder having an external cylindrical surface 3122. End 3026 of hose3020 is mounted over cylindrical surface 3122 and is preferably securedby a hose clamp (not shown).

Center portion 3118 is formed adjacent support section 3116 and has anouter annular surface 3124 and an inner cylindrical cavity through whichshaft 12 passes and in which shaft 12 rotates. Surface 3124 has adiameter greater than the diameter of surface 3122.

Sealing section 3120 is formed adjacent center portion 3118 oppositesupport section 3116. Sealing section 3120 has an outer annular surface3126, a generally flat radial sealing face 3128, and an inner cavity(not shown) for receiving shaft 12.

The respective inner cavities of support section 3116, center portion3118 and sealing section 3120 align to form one continuous cylindricalcavity through friction ring 3090, through which shaft 12 passes.

Seal ring 161, which is preferably formed of stainless steel, isprovided on shaft 12 adjacent sealing section 3120. Seal ring 161 iscircular and has an annular outer surface 3054 and an annular innersurface within which shaft 12 is located when device 3010 is mounted foroperation. Sealing surface 160 which is generally flat and radial andextends between outer surface 3054 and the inner annular surfacedefining the bore for shaft 20. Sealing surface 160 is parallel to andsealingly engages sealing face 3128 of friction ring 3090.

A shaft clamp or collar 163 is cylindrical and tightly fitted onto shaft12 by means of a clamping screw 167. Shaft clamp 163 has a side 3160formed along a side facing seal ring 161. An inner annular surface ofside 3160 of collar 163 is contained on side 3160 for defining theentrance to the bore for receiving shaft 20.

Biasing or loading means 3130, which are preferably a set of stainlesssteel springs 3132, are connected at one end to the inner surface ofside 3160 of shaft clamp 163 and connected at the other end to thesurface 3158 of seal ring 161. In this respect, side 3160 of collar 163contains four radially-spaced bores which receive the ends of springs3122 and surfaces 3158 of seal ring 161 contains four radially-spacedbores (not shown) in registry with the bores in side 3160, which receivethe other ends of springs 3122. In a preferred embodiment, there arefour or more equally radially-spaced biasing means forming biasing means3130. A biasing means cover 3134 is a generally tubular, flexible memberhaving ends 3138 and a center 3140. One end fits over a recessed end3159 of side 3160 and is clamped in place by a hose clamp 3162. Theother end 3138 fits over outer annular surface 3054 of seal ring 161 andis clamped in place by a hose clamp 3162. Center 3140 is generally of abellows construction, allowing for the compression and extension ofcover 3134 as discussed earlier with respect to the forward and rearwardshifting of seal ring 161.

Turning now to FIG. 26, a fifth embodiment 4010 of the present inventionis shown mounted around shift 12. Device 4010 basically comprises anadapter ring 4020, a friction ring 4090, a biasing means 4130, a sealring 161 and a shaft clamp 163. Adapter ring 4020 is generally a hollow,cylindrical tube having an outer, annular surface 4022 and an innercavity for receiving shaft 12. A first end 4024 includes a radial, flatmating surfaces. A second end 4026 includes attachment means forattachment to thru-hull adapter ring 142 or the like, as described indetail above.

A base member 4112 is generally a hollow, cylindrical member having anouter, annular surface 4116, a first bore 4118 and a second bore 4120.Bore 4118 extends approximately half way into friction ring, 4090 alongaxis A and has annular surface 4122 and a support surface 4124 which isgenerally flat and annular. Second bore 4120 is cylindrical and orientedabout axis A and extends from first bore 4118 through the end 4126 offriction ring 4090 adjacent adapter ring 4020. Second bore 4120 is,therefore, in communication with the inner bore of adapter ring 4020 andhas an annular wall 4128 for receiving shaft 12.

Friction ring 4090 is generally a cylindrical ring having an annularouter surface 4132 and an annular inner surface which defines acylindrical bore, the bore having a diameter larger than the diameterthan the diameter of shaft 12. Friction ring 4090 has a first end 4134which includes a generally flat, surface between the inner annularsurface and outer annular surface 4132. A second end 4136 includes aflat sealing surface 4160 extending between the inner annular surfaceand the outer annular surface 4132.

Biasing means 4130 is generally comprised of a cylindrical stainlesssteel spring surrounding shaft 12. One end of spring 4130 engagessurface 4124 of base 4112 and the other end of spring 4130 engagessurface 4134 of friction ring 4090.

A seal ring 161 is provided on shaft 12 and is preferably formed ofstainless steel. Ring 161 is generally cylindrical and has a flat radialsealing surface 160 which mates with and sealingly engages the sealingsurface 4126 of friction ring 4090 on second end 4136. A shaft clamp 163is provided on shaft 12 adjacent to and connected to seal ring 161. Aclamping screw 167 is used to tighten clamp 163 to shaft 12 therebyholding seal ring 161 in a fixed position on shaft 12. The axialadjustment of the apparatus described in FIG. 26 is the shaft drives theship fore and aft is as discussed earlier.

Turning now to FIG. 27, a sixth embodiment 5010 of the present inventionis shown installed on propeller drive shaft 12. Device 5010 has anadapter ring 5020 which is a short, hollow, cylindrical tube having afirst end 5022 and a second end 5024. Second end 5024 contains anattachment means for the thru-hull adapter ring 142, as described indetail above, or to some other means for connecting the seal assembly tothe hull or bulkhead. Adapter ring 5020 has a cylindrical exterior wall5026 and an interior cavity through which shaft 12 passes.

Gasket or diaphragm 5050 includes an annular base, a leg and an annularfoot similar to those of gasket 50 and best seen in FIGS. 2, 3, 9, 10and 11. Base 5052 is mounted on surface 5034 of adapter ring 5020.

Slide ring 5062 has an exterior cylindrical surface 5064 and an innercavity which communicates with the inner cavity in adapter ring 5020 forreceiving shaft 12. Slide ring 5062 has a first end 5066 including agenerally flat, radial surface which compresses gasket 5050. A secondend 5068 of slide ring 5062 includes a generally flat, radial surface.Cylindrical bores 5070 are equally radially spaced about the annularsurface of side 5068.

Friction ring 5090 has generally an elongated, hollow, cylindricalcylinder 5101 having a cylindrical surface 5092 and an interior cavitythrough which shaft 12 passes. A first end of friction ring 5090 iscontained within the cavity formed by slide ring 5062 and adapter ring5020 seals against water with gasket 5050. A second end 5094 of cylinder5101 is attached to or integrally formed with a second hollow cylinder5110 discussed below of friction ring 5090.

Friction ring 5090 includes two additional integrally formed, generallyconcentric hollow cylinder 5110 and friction ring seal member 5114.Cylinder 5110 has an outer annular surface 5116, a first side 5118 andan second side 5120. Sides 5118 and 5120 are generally radial and flatand are on opposite sides of cylinder 5110. Friction ring seal member5114 is formed adjacent cylinder 5110, and on the opposite side ofcylinder 5110 from cylinder 5101. Friction ring seal member 5114includes an annular outer surface 5122 and has a first end 5124 whichincludes a generally flat, radial sealing surface 5126. Sealing surface5126 engages seal surface 160 of seal ring 161. A plurality of bores5128 extend through cylinder 5110, bores 5128 being in registry withbores 5070 in slide ring 5062.

Biasing or loading means 5130, each of which is preferably a stainlesssteel spring 5132 inserted onto posts 5134, wherein posts 5134 arepreferably made of steel. Posts 5134 are elongated steel bars and eachhas a first end 5135 and a second end 5136. The respective first ends5135 of posts 5134 are inserted into bores 5070 in surface 5068 of slidering 5062. The second ends 5136 of posts 5134 are inserted into bores5128 of cylinder 5110, and extend through cylinder 5110. In a preferredembodiment there are four posts 5134 each having springs 5132, equallyradially spaced about cylinder 5101. Springs 5132 are retained bysurface 5068 at one end and by surface 5118 at the other end. Theadjustment of apparatus 5010 as shaft 12 moves the vessel fore and aftis as described earlier.

Turning now to FIG. 28, a seventh embodiment 6010 of the presentinvention is shown installed on a propeller drive shaft 12. Device 6010is identical in all respects to device 5010, which is described indetail above, except for the biasing or loading means 6130. Thus, device6010 includes an adapter ring 6020, a diaphragm 6050, a slide ring 6062,and friction ring 6090. Biasing or loading means 6130, similar tobiasing means 5130, are comprised of posts 6134, which are preferablystainless steel shafts. Posts 6134 have ends 6135 and ends 6136. Bothends 6135 and 6136 are threaded so as to be threadingly received inrespective nuts 6137. Nuts 6137 are fastened to the surface 6068 ofslide ring 6062 and to surface 6120 of ring 6110.

A hose adapter is another embodiment of the invention. Turning to FIGS.29 and 30, a hose adapter 6500 is shown. Hose adapter 6500 is comprisedof a threaded portion 6502 whose threads are dimensioned and configuredto mate with threads 44 of adapter ring 20, so that the hose ring can bescrewed into adapter ring 20. Threaded portion 6502 terminates at aflange 6504, from which a hose support 6506 extends on the opposite sideof the flange from threaded portion 6502. A cylindrical bore 6508extends through hose adapter 6500 receiving shaft 12. As explainedlater, hose adapter 6500 is screwed adapter ring 20, so that hoseconnection 6506 extends towards the hull of the vessel. The end of thehose can be slid onto hose connection 6506 and held in place by a hoseconnection system.

The insertion of hose adapter 6500 into adapter ring 20 is very simple,as is the connection of the hose to hose connector 6506. Bore 6508 isaligned with other bores through which the vessel shaft extends, so thatthe hose adapter is easy to install on a vessel with the assembledshaft.

A stern tube adapter 7002 is depicted in FIG. 31. Tube adapter 7002includes a tube ring 7004 having an externally threaded portion 7006with threads being adapted for mating with internal threads 44 ofadapter ring 20. A shaft-receiving bore 7008 extends through theengine-facing side of tube adapter 7002 for receiving shaft 12 forrotation. The hull-facing side of tube adapter 7002 has a wider borehaving an inner diameter which is lager than the outer diameter of afiberglass stern tube 7012 which extends from bore 7010 through the hullof the vessel. A shoulder 7014 is provided at the interior end of bore7010 for abutment with stern tube 7012. Four screw bores 7016 areequilaterally provided through adapter 7002 into bore 7010 for receivingcentering screws 7018. Screws 7018 have threaded shanks for enablingscrews 7018 to be threaded into bores 7016, and a hexagonal head 7020for inserting and removing screw 7018 from bore 7016. Screws 7018 areinserted into bore 7016 for engaging stern tube 7012 to locate the sterntube concentrically about shaft 12.

It can be seen that the installation of stern tube adapter 7002 ontoadapter ring 20 is a simple procedure, and that stern tube 7012 caneasily be installed to adapter 7002.

FIG. 32 shows as another embodiment of the invention a stern tube sealassembly 7500. This embodiment provides a stern tube seal assemblyhaving a stern tube 7502 which is operatively connected to the shaftseal system. In the assembly shown in FIG. 32, many of the members areidentical to members discussed in earlier embodiments of the invention,and are given their previous numbers, with reference being given tothose earlier parts of the application in which those members arediscussed in further detail.

Stern tube 7501 is a custom component, having a section 7502 near hull14, and a component 7503 dimensioned for attachment to adapter ring 20.Stern tube 7501 is fiberglass, and it is secured by fiberglassing or anappropriate cement to the hull. Tube 7501 is in effect an integral partof hull 14. Parts of the assembly in FIG. 32 are the same as thosediscussed earlier, and have been designated with the same numericalidentifiers. There are sea gasket or diaphragm 50, slide ring 62,centering screws 82 which extend through bores in slide ring 62 and intoappropriately aligned bores 7504 in the internal end portion of sterntube 7502 to center the assembly about cylinder 12, friction ring 90,spring 130, spring cover 134, seal ring 161 and shaft clamp 163. Asexplained earlier, there is a redundant seal against water leaking fromthe confines of the shaft seal system into the boat by virtue ofdiaphragm 50 and spring cover 134, even if there is longitudinal ortransverse movement of shaft 12. The assembly is entirely rigid from thehull through the stern tube and the shaft seal system. The stern tubeassembly and the shaft seal system can be installed from the engine sideof the shaft by sliding the shaft seal system 10 on the shaft towardsstern tube 7501, inserting centering screws 102, then inserting sealring 161 arid sliding shaft clamp 163 in place, connecting shaft clamp163 to seal ring 161 with screws 165, and tightening clamp screws 167 tosecure shaft clamp 163 to shaft 12.

An air seal assembly 7600 according to another version of the inventionis shown in FIG. 33 and the incorporation of assembly 7600 with shaftseal system 10 is shown in FIG. 34. The air seal assembly is anemergency device, and is activated to engage shaft 12 which should notbe rotating. As explained earlier, system 10 includes adapter ring 20,gasket 50, slide ring 62, centering screws 82, friction ring 90, spring130, spring cover 134, O-rings 169, seal ring 161 and shaft clamp 163.The earlier descriptions can be referred to for a discussion of theseand related components. Air seal assembly 7600 is composed of an airseal adapter (female thread) 7602), an air seal adapter (male thread)7604, an air seal 7606 and an air valve assembly 7608. The male air sealadapter has an extending portion 7610 with external threads 7611 adaptedand configured to be screwed into the receiving threads 42 of adapterring 20. Air seal 7606 is a plastomeric annular component having aninternal chamber 7612 which can be filled with air under pressureflowing through nozzle 7613 and a bored stem 7614 of air valve 7608. Thepressurized air enters chamber 7612 through an appropriately dimensionedand configured inlet port 7616, to expand and engage shaft 12, toprevent or reduce the flow of water along the shaft. A radial bore 7618through air seal adapter 7604 is dimensioned to receive stem 7614without allowing air or water to flow between bore 7618 and stem 7614. Aset of longitudinally extending connection screws 7620 connect air sealadapters 7602 and 7604, through aligned, receiving bores in adapters7602 and 7604. An O-ring 7622 is located in recesses 7624 of adapterring 20 and 7626 in air adapter 7602 to further enhance the seal betweenair seal adapter 7604 and adapter ring 20, and air seal adapter 7602 andits adjacent part. A longitudinal bore extends through air seal adapters7602 and 7604 to receive shaft 12 for rotation. Internally threadedreceiving bore 7628 is provided for receiving a thru-hull adapter ringor other adapters mentioned previously for connection of the air sealadapter to the hole in the hull. The air seal adapters are made fromstrong, non-corrosive materials such as delrin. The air seals areavailable in the marketplace from Duramax, Inc., and at least one ismade from nitrile.

A stern tube clamp assembly 8000 is shown in FIG. 35 for use with astern tube 7012 as shown in FIG. 31. Stern tube clamp assembly 8000 isanother attachment which can be used with shaft seal adapter 10. Anadapter clamp 8002 has an extending, externally threaded portion 8004 tobe screwed into adapter ring 20. A stern tube clamp 8006 is clampedaround stern tube 7012 and held in place by clamp screws 8008. Sterntube clamp 8006 and adapter clamp 8002 are connected together by a setof connecting screws 8009 which extend through aligned bores 8010 and8012 of shaft clamp 8006 and adapter clamp 8002. Stern tube 7012 isintegrally connected with the hull of the vessel as explainedpreviously. Shaft receiving bores extend through adapter clamp 8002 andshaft clamp 8006. An O-ring 8014 is disposed at the intersection ofadapter clamp 8002, stern tube clamp 8006 and the exterior of stern tube7012 to add another seal to the assembly. In order to assembly the sterntube seal assembly, stern tube clamp 8006 is slid onto stern tube 7012,O-ring 8014 is placed at the inner edge of stern tube clamp 8006, andadapter clamp 8002 is then slid on until its internal shoulder 8016abuts the end of stern tube 7012. The clamps are attached by connectingscrews 8008, and the stern tube clamp assembly is then screwed toadapter ring 20. Adapter clamp 8002 and stern tube clamp 8006 are madefrom delrin or some other strong, corrosion-resistant material.

A hose bearing adapter assembly 8500 is illustrated in FIGS. 36 and 37.Assembly 8500 is yet another attachment possible with shaft seal adapter10. It includes a hose adapter 8502 having an externally threadedextension 8504 to be attached to adapter ring 20 by being screwed intointernal threads of section 42 of ring 20. The hose adapter 8502 has arelatively long extension 8506 for receiving along an internal bore, abearing 8507 which can he made from a rubber-like material, and whichabuts at shoulder 8508. A radially threaded bore 8510 is provided forreceiving a set screw to hold the bearing 8507 in place. An outsidecylindrical surface 8512 receives a hose 9514 with extends beyondextension 8506 towards and onto a stern tube which is integral to thehull of the vessel at the hole through which the shaft extends. Hose8514 is held on hose adapter ring 8502 by hose clamps 8516. Alongitudinal shaft-receiving bore 8518 extends through hose adapter ring8504. The cross-sectional view shown in FIG. 37 includes the wide partof hose adapter ring 8504, the extension 8506 and bearing 8507 havinglongitudinally extending, generally semi-circular recesses 8520. Hoseadapter ring 8502 should be made of a strong, corrosion-resistantmaterial such as delrin.

Assembly of hose bearing adapter assembly 8502 is easy. Bearing 8507 isinserted into the bore of extension 8506 until it abuts shoulder 8508.The end of hose 8514 is then slid on surface 8512 and clamped in placeby hose clamps 8516. A set screw is screwed into bore 8510. The assembly8500 is then connected to adapter ring 20.

The invention according to its preferred embodiment provides aneffective and efficient device for preventing water leakage along thepropeller shaft into a vessel. The shaft seal system is rigid to preventdamage and leakage from impacts to the system, it can be easilyinstalled without removing a vessel from the water, and it is corrosionand wear-resistant. Many attachments can be used with the shaft sealsystem for use with many types of vessels, and these attachments areeasy to install, and effective and efficient in use.

The invention has been described in its preferred forms, bit variationsand modifications within the spirit and scope of the invention may occurto those skilled in the art from the preceding description and in theappended claims.

What is claimed is:
 1. A hose adapter in combination with a shaft sealsystem for sealing against water leakage along the propeller shaft of avessel extending from an opening in the hull of the vessel to an adapterring of said shaft seal system, the adapter ring having ashaft-receiving bore and a component attachment means comprising screwthreads for attachment of the adapter ring to other components of saidsystem, the adapter ring having a fore end portion operativelyconnectable to an inboard fluid seal system and an aft end portionconnectable to at least one component extending from an opening in thehull of the vessel, said adapter comprising:shaft-receiving fore meanshaving a bore for receiving the propeller shaft and for alignment withthe shaft-receiving bore of the adapter ring; adapter ring attachmentmeans for attaching said adapter to the aft end portion of the adapterring to align said shaft-receiving bore means of said adapter with theshaft-receiving bore of the adapter ring, said adapter ring attachmentmeans comprises a threaded portion operatively engagable with the screwthreads of the adapter ring; coupling means for coupling ashaft-receiving tubular means extending from the hull to said adapter,said coupling means comprising a cylindrical extension for receiving ahose extending towards the hull for coupling the propeller shaft andpreventing water leakage; and said adapter being rigid to reduce anydamage caused by any impact transverse to said adapter.
 2. A sealingdevice for sealing against water leakage from a propeller shaft and avessel wall into which the shaft passes, said device comprising:sterntube means connectable to the wall and having a bore for receiving theshaft for rotation; generally rigid slide ring means stationary withrespect to the shaft and having a bore for receiving the shaft forrotation, said slide ring means operatively attachable to said sterntube means; generally rigid friction ring means having a bore forreceiving the shaft for rotation, and a friction ring seal surface forengagement with a sealing surface rotatable with the shaft forestablishing a watertight seal, said friction ring means being attachedto said slide ring means in a moveable relationship, said friction ringmeans being independent of said slide ring means and being movablerelative to said slide ring means; biasing means for urging saidfriction ring seal surface into engagement with the sealing surfacerotatable with the shaft; and diaphragm means connected to said slidering means and to said friction ring means for preventing water fromflowing to said biasing means.
 3. A fluid sealing device for a propellerdrive shaft extending through an opening in the hull of a vessel, theshaft having a generally linear axis and having seal ring means with aseal ring seal surface, the seal ring means being mounted to the shaftfor rotation with the shaft, said device having a shaft-receivingpassageway and comprising:adapter ring means having an aft end forconnection to different types of adapters extending through the openingin the hull; friction ring means having a friction ring seal surface forengaging the seal surface to create a watertight seal; biasing means forexerting a biasing force on said friction ring means to provide for theengagement of said friction ring seal surface and the seal ring sealsurface; resilient means for preventing the flow of water along theshaft, said resilient means extending or retracting with the fore andaft movement of the shaft and said friction ring means; slide ring meansattached to said resilient means for preventing the movement of saidresilient means along the axis of the shaft, said slide ring means beingindependent of said friction ring means and movable relative to saidfriction ring means; and support means for supporting said biasing meansbetween said slide ring means and said friction ring means; saidfriction ring means being movable relative to said slide ring means andto said support means, in response to movement of the shaft, while saidfriction ring means is biased by said biasing means to maintain theengagement of said friction ring seal surface and the seal ring sealsurface.
 4. A fluid sealing device according to claim 3, wherein saidbiasing means comprise a plurality of springs, and said support meanscomprise a plurality of supports for each of said springs.
 5. A fluidsealing device according to claim 4, wherein said supports are fixed tosaid slide ring means, and wherein said device further comprises meansfor retaining said biasing means on the respective support means toenable said biasing means to continuously keep the biasing force on saidfriction ring means.
 6. A fluid sealing device according to claim 5,wherein said supports are posts fixed in said slide ring means andextending through a portion of said friction ring means, and whereinsaid springs are wound about said supports.
 7. A fluid sealing deviceaccording to claim 3, wherein said resilient means comprises adiaphragm.